23) Nantlle vale (Dyffryn Nantlle) Nantlle vale is one of the three great slate quarrying areas of North Wales, the others being the Bethesda - Llanberis area in the north, and that of Ffestiniog further south. Each of these areas used different techniques to extract the slate (although producing a more or less standard product) which has resulted in markedly different topographical characteristics in each area. The reason for these differences is the varying formation of the slate beds in the surrounding rocks. As has already been seen at Penrhyn and Dinorwic, the slate strata of Cambrian rock outcrops directly on the side of the mountain there, and can be extracted by simply quarrying into the hillside. At Nantlle however these same beds have a much steeper, near-vertical dip and outcrop on the valley floor. In order to quarry this slate, pits have to be dug down into the strata and the slate blocks hauled out. This form of quarrying and the vertical dip of the beds have led to the characteristic landscape of deep, vertically sided pits (twllau), now frequently flooded, and overlooked by the slate rubbish tips. Quarrying at Nantlle goes back many hundreds of years. The first slate quarry in Wales was probably that at Cilgwyn, which produced roofing slate for local use on a small scale in the mediaeval period. Very little in the way of systematic working of the slate was attempted until the roads to the nearest point of shipment (Caernarfon) had been sufficiently improved to justify expenditure on development. This situation had come about by c.1800, whereupon the Crown common land began to be leased to local gentlemen and merchants who started to capitalise and enlarge the existing quarries and open new ones. Although more money was now available, none of the early companies was wealthy enough to undertake quite the same sort of extensive development that was being carried out at Penrhyn and Dinorwic at this time. As a result, no large quarry to rival the two giants emerged despite early hopes for Cilgwyn, and the pattern of a number of quarries run by different companies - the ownership frequently changing due to bankruptcy and sale - was to remain. The district can best be approached from the west along the road from Talysarn village. This was the original line of the main road to Rhyd-Ddu (B4418) and it passed straight through the quarrying area until encroachment of the pits forced it to be rerouted in the 1920’s. A 3 ft 6 in gauge horse-drawn tramway carrying slate from the pits ran down to the old L&NWR branch terminus station at Talysarn until as late as 1965: the course of this can be seen (489531) first on the right then on the left side of the road, in some places tunneling under the front gardens of the adjacent houses. This line was the sole remaining portion of the 3 ft 6 in gauge Nantlle Railway of 1828, established to expedite the transport of slate from the quarries to the port of Caernarfon, to which it originally ran. The construction of the railway eliminated the long haul over difficult roads to the port, but the sections west of Talysarn were later taken over by standard gauge railway companies who rebuilt and realigned them: that beyond Pen-y-Groes by the Carnarvonshire Railway Co. in 1867, and that between Pen-y-Groes and Talysarn by the L&NWR Co. in 1872. The road and railway eventually pass under separate arches in a tall slate slab bridge known as Pont Fawr (494532; pictures right). This bridge connected parts of the Talysarn slate quarry, and the most notable event in its life was in January 1879 when a quarry locomotive fell off it and was destroyed. Our colour picture shows the Nantlle Tramway rails still in place in 1967….. On passing under the bridge one enters the main quarrying area, where to the left can be seen the water-filled pit or “twll” of the Talysarn quarry. As all the quarried slate in the Nantlle area had to be raised up out of deep pits (waste rock included) a method other than the simple gravity inclines used elsewhere had to be found to bring the material to the mills and tips. The system adopted was the use of aerial ropeways, known variously as “Blondins” or “Jerry M’s”. A cable was strung across the pit, along which ran a small cradle with a wheel at each end. From this cradle hung further cables, terminating in a chain sling that could be attached to the body of the tram wagons. One of these wagons, running on temporary railway lines at the base of the pit, would be loaded with slates and moved into the central area to be attached to the chain of the “Blondin”. It was then lifted vertically to the top surface level of the pit; whence the cradle with wagon attached could then be hauled in horizontally until over the landing stage at the upper level. Here the wagon is lowered onto further tracks; the waste could be tipped and good slate taken to the mills either on this level or on a lower one down conventional inclines. This was the system at its simplest; often the waste and good slate would be landed at different points, and frequently there would be several Blondins in operation over one pit. A landing stage for the Talysarn quarry can be seen on the left of the pit; from there the slate was taken on the level to the tips and mills across the high bridge. On the south side of the road two inclines leave the main tramway route and if the shorter, left-hand one is climbed, a walk round the tips will lead to an impressive general view of the workings. Directly ahead can be seen the vast 600 ft deep pit of the Dorothea Slate Quarry, started in 1829 and named after the wife of the landlord, Richard Garnons esq. (1774-1844); it was worked until 1970 and has since become flooded (photo right by David Mills). A path leads down from here to the best- preserved and grandest relic of the Nantlle Vale quarries, the Dorothea pumping engine. This is a Cornish beam engine with 68 inch diameter cylinder, built by Holman brothers of Camborne in 1904, used to keep the great main pit dry. It cost the company £1,925 new and was one of the very last of the big Cornish engines built. It worked continuously until 1955 when it was superseded by electric pumps, then was retained for emergency use. It is basically complete, with the steam winch and shearlegs used for replacement of the wooden pump rods, and two Lancashire boilers survive in the roofless boiler house. Although mainly in a good state of preservation (some restoration work having been undertaken by the Industrial Steam Preservation Group) the future of this fine engine at the time of writing is uncertain. All except the first of this set of pictures were taken by David Mills….. This picture shows the Dorothea Quarry war memorial plaque, made, naturally from its own slate, which is positioned on the main side wall of the engine house……. The image below looks across the valley from the north side of the Talysarn Quarry pit, with the engine house right of centre, and an incline to its left. The roof of the large Dorothea mills building is seen left of centre; the big pit is to the left again and below, hidden by the trees here….. Just beyond the engine house are an interesting collection of buildings, inclines and earthworks around the edge of the main pit. A smithy is on the left; behind and above it the remains of one of the aerial ropeway stations. The wooden head-frames hang out over the sheer side of the pit, and the building formerly occupied by the horizontal steam winding engine survives with its lean-to boiler house alongside. Towering above this site is a vast dry-walled slate-slab bastion on the edge of the slate tips which once supported another cableway system; it is visible just above centre of the left hand picture above. The landing stage and the building that housed two overtype locomotive boilers for powering stationary steam engines can be identified (picture right, by David Mills) Nearby, one of the quarry steam locomotives, the small Hunslet “Dorothea” remained in very derelict condition in its collapsed shed until 1972, when it was finally removed for preservation. In the background of our 1969 picture, below left, some of the wooden headframes for the Blondin ropeway systems are seen. A long transporter-type incline connects the waste tips with ground level. Following the edge of the pit brings one to the site of the huge main Dorothea dressing mill (complete until recently; picture below right). The engine and boiler house at one time used to drive the line shafting can still be found at the rear of the buildings. Returning to the Talysarn quarry at (495533), the track of the main Nantlle tramway can be followed. On the hillside above this (498536; at the top of Blaen-y-Cae quarry) there is a small steam winding engine used for driving the aerial ropeway, inscribed “Henderson Cableway, Aberdeen, Scotland”. This machine comprises a complete unit with winding drum, two inclined cylinders with reversing gear, and driving position. It was probably latterly powered by compressed air……. The Nantlle Tramway curves round the back of Talysarn Hall, with its stable block (right) adjacent.